CONDENSED STATEMENTS OF CASH FLOWS - USD ($)	6 Months Ended
	Jul. 31, 2022	Jul. 31, 2021
Operating activities
Royalties received	$ 15,857,438	$ 25,835,075
Interest received	25,666	797
Expenses paid	(1,216,251)	(2,221,401)
Net cash from operating activities	14,666,853	23,614,471
Investing activities
Maturities of U.S. Government securities	49,166,956	50,942,392
Purchases of U.S. Government securities	(72,503,643)	(41,035,723)
Net cash from (used for) investing activities	(23,336,687)	9,906,669
Financing activity
Distributions to unitholders	(36,604,828)	(17,712,014)
Net change in cash and cash equivalents	(45,274,662)	15,809,126
Cash and cash equivalents, beginning of period	47,727,522	12,500,941
Cash and cash equivalents, end of period	2,452,860	28,310,067
Reconciliation of net income to net cash from operating activities
Net income	8,737,814	35,329,900
Decrease (increase) in accrued income receivable	4,622,034	(12,385,176)
Decrease in contract asset	1,431,633	177,251
Increase in prepaid expense	(176,940)	(193,751)
Increase (decrease) in accrued expenses	52,312	(210,684)
Increase in contract liability		896,931
Net cash from operating activities	14,666,853	23,614,471
Non cash financing activity
Distributions declared and payable	$ 11,020,810	$ 1,180,801